Conventionally, one may charge hybrid and electrical vehicles by a connecting cable using a supply network. Electrical supply networks supply an alternating voltage of 230 V (or other standardized voltage values, such as 110 V), which, however, on the one hand, based on the high value of the voltage, and on the other hand, based on its type, that is, alternating voltage, is not directly suitable for charging accumulators of electrically operated vehicles. Accumulator devices for the traction of electrically operated vehicles require DC voltage, the charging current being defined by the level of the DC voltage.
For charging accumulator devices, using an alternating voltage supply network, it is therefore necessary to provide an alternating current/direct current converter which rectifies, for one thing, and supplies a direct voltage having an adjustable and suitable level for another. The direct voltage may also be fixed ahead of time, as a function of the charging mechanism, in which case, however, in usual supply networks of 230 V or 110 V, no suitable voltage level is able to be achieved by mere rectification.
Therefore, alternating current/direct current converters are required which are conventionally provided particularly at the accumulator device, generally within the vehicle.
Consequently, in conventional charging processes, the connection between an alternating current interconnected network and a vehicle is a simple cable, via which, for charging the accumulators, the vehicle is connected to an alternating voltage supply network. On the one hand, the conversion as well as the adjustment to the suitable voltage level is provided within the vehicle, so that, for different supply networks, there is compatibility, especially when vehicles are exported to countries having different supply voltages. On the other hand, alternating current/direct current converters have to be designed specifically for the accumulator device and specifically for the voltage, which an interconnected network, i.e., the electrical supply, provides in an area in which the vehicle is being operated.